From d628ee4fef1dbd6f2fa11e3548322c7839319537 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Thu, 14 May 2020 12:51:20 +0200 Subject: [PATCH] mlx5: Rx queue setup time determine frame_sz for XDP The mlx5 driver have multiple memory models, which are also changed according to whether a XDP bpf_prog is attached. The 'rx_striding_rq' setting is adjusted via ethtool priv-flags e.g.: # ethtool --set-priv-flags mlx5p2 rx_striding_rq off On the general case with 4K page_size and regular MTU packet, then the frame_sz is 2048 and 4096 when XDP is enabled, in both modes. The info on the given frame size is stored differently depending on the RQ-mode and encoded in a union in struct mlx5e_rq union wqe/mpwqe. In rx striding mode rq->mpwqe.log_stride_sz is either 11 or 12, which corresponds to 2048 or 4096 (MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ). In non-striding mode (MLX5_WQ_TYPE_CYCLIC) the frag_stride is stored in rq->wqe.info.arr[0].frag_stride, for the first fragment, which is what the XDP case cares about. To reduce effect on fast-path, this patch determine the frame_sz at setup time, to avoid determining the memory model runtime. Variable is named frame0_sz to make it clear that this is only the frame size of the first fragment. This mlx5 driver does a DMA-sync on XDP_TX action, but grow is safe as it have done a DMA-map on the entire PAGE_SIZE. The driver also already does a XDP length check against sq->hw_mtu on the possible XDP xmit paths mlx5e_xmit_xdp_frame() + mlx5e_xmit_xdp_frame_mpwqe(). V3+4: Change variable name first_frame_sz to frame0_sz V2: Fix that frag_size need to be recalc before creating SKB. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov Acked-by: Tariq Toukan Cc: Saeed Mahameed Link: https://lore.kernel.org/bpf/158945348021.97035.12295039384250022883.stgit@firesoul --- drivers/net/ethernet/mellanox/mlx5/core/en.h | 1 + drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c | 1 + drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 6 ++++++ drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 2 ++ 4 files changed, 10 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h index 3bd64c63865b..26911b15f8fe 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h @@ -625,6 +625,7 @@ struct mlx5e_rq { struct { u16 umem_headroom; u16 headroom; + u32 frame0_sz; u8 map_dir; /* dma map direction */ } buff; diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c index c4a7fb4ecd14..761c8979bd41 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c @@ -137,6 +137,7 @@ bool mlx5e_xdp_handle(struct mlx5e_rq *rq, struct mlx5e_dma_info *di, if (xsk) xdp.handle = di->xsk.handle; xdp.rxq = &rq->xdp_rxq; + xdp.frame_sz = rq->buff.frame0_sz; act = bpf_prog_run_xdp(prog, &xdp); if (xsk) { diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c index 0a9dfc31de3e..0e4ca08ddca9 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -462,6 +462,8 @@ static int mlx5e_alloc_rq(struct mlx5e_channel *c, rq->mpwqe.num_strides = BIT(mlx5e_mpwqe_get_log_num_strides(mdev, params, xsk)); + rq->buff.frame0_sz = (1 << rq->mpwqe.log_stride_sz); + err = mlx5e_create_rq_umr_mkey(mdev, rq); if (err) goto err_rq_wq_destroy; @@ -485,6 +487,8 @@ static int mlx5e_alloc_rq(struct mlx5e_channel *c, num_xsk_frames = wq_sz << rq->wqe.info.log_num_frags; rq->wqe.info = rqp->frags_info; + rq->buff.frame0_sz = rq->wqe.info.arr[0].frag_stride; + rq->wqe.frags = kvzalloc_node(array_size(sizeof(*rq->wqe.frags), (wq_sz << rq->wqe.info.log_num_frags)), @@ -522,6 +526,8 @@ static int mlx5e_alloc_rq(struct mlx5e_channel *c, } if (xsk) { + rq->buff.frame0_sz = xsk_umem_xdp_frame_sz(umem); + err = mlx5e_xsk_resize_reuseq(umem, num_xsk_frames); if (unlikely(err)) { mlx5_core_err(mdev, "Unable to allocate the Reuse Ring for %u frames\n", diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c index 779600bebcca..821f94beda7a 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c @@ -1070,6 +1070,7 @@ mlx5e_skb_from_cqe_linear(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe, if (consumed) return NULL; /* page/packet was consumed by XDP */ + frag_size = MLX5_SKB_FRAG_SZ(rx_headroom + cqe_bcnt); skb = mlx5e_build_linear_skb(rq, va, frag_size, rx_headroom, cqe_bcnt); if (unlikely(!skb)) return NULL; @@ -1371,6 +1372,7 @@ mlx5e_skb_from_cqe_mpwrq_linear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *wi, return NULL; /* page/packet was consumed by XDP */ } + frag_size = MLX5_SKB_FRAG_SZ(rx_headroom + cqe_bcnt32); skb = mlx5e_build_linear_skb(rq, va, frag_size, rx_headroom, cqe_bcnt32); if (unlikely(!skb)) return NULL; -- 2.30.2